Spin- and time-resolved photoelectron spectroscopy and diffraction studies using time-of-flight momentum microscopes

Abstract

Momentum microscopy (MM) is a novel way of performing angular-resolved photoelectron spectroscopy (ARPES). Combined with time-of-flight (ToF) energy recording, its high degree of parallelization is advantageous for photon-hungry experiments like ARPES at X-ray energies and spin-resolved ARPES. This article introduces into the spin-resolved variant of ToF-MM and illustrates its performance by selected examples obtained in different spectral ranges. In a multidimensional view of the photoemission process, spectral density function $\rho (k,E_B)$, spin polarization $P(k,E_B)$ and related quantities of circular dichroism in the angular distribution (CDAD) are part of the complete experiment, a concept adopted from atomic photoemission. We show examples of spin-resolved valence-band mapping in the UV, VUV, soft- and hard-X-ray range. Spin mapping of the Heusler compounds Co${}_2$MnGa and Co${}_2$Fe${}_{0.4}$Mn${}_{0.6}$Si at $h\nu =6$~eV prove that the second compound is a half-metallic ferromagnet. Analysis of the Tamm state on Re(0001) using VUV-excitation reveals a Rashba-type spin texture. Bulk band structure including Fermi surface, Fermi velocity distribution $v_F(k,E_F)$, full CDAD texture and spin signature of W(110) have been derived via tomographic mapping with soft X-rays. Hard X-rays enable accessing large k${}_{par}$-regions so that the final-state sphere crosses many Brillouin zones in $k$-space with different $k_z$. At $h\nu =5.3$~keV this fast 4D mapping mode (at fixed $h\nu$) revealed the temperature dependence of the Fermi surface of the Kondo system YbRh${}_2$Si${}_2$. Probing the true bulk spin polarization of Fe${}_3$O${}_4$ at $h\nu =5$~keV proved its half-metallic nature. The emerging method of ToF-MM with fs X-ray pulses from a free-electron laser enables simultaneous valence, core-level and photoelectron diffraction measurements in the ultrafast regime.

arXiv commentJVST Special collection Commemorating Charles S. Fadley

References in corpus (55)

• Topological States on the Gold Surface
• Discovery of topological Weyl fermion lines and drumhead surface states in a room temperature magnet
• Generation of phase-matched circularly-polarized extreme ultraviolet high harmonics for magnetic circular dichroism spectroscopy
• Extrinsic Magnetotransport Phenomena in Ferromagnetic Oxides
• Computational Investigation of Half-Heusler Compounds for Spintronics Applications
• Directly visualizing the momentum forbidden dark excitons and their dynamics in atomically thin semiconductors
• Angle-resolved photoemission spectroscopy and its application to topological materials
• Jahn-Teller stabilization of a "polar" metal oxide surface: Fe3O4(001)
• Formation of moiré interlayer excitons in space and time
• Spin-orbit splitting of the Shockley surface state on Cu(111)
• Examining electron-boson coupling using time-resolved spectroscopy
• Coincidence velocity map imaging using Tpx3Cam, a time stamping optical camera with 1.5 ns timing resolution
• Mapping momentum-dependent electron-phonon coupling and non-equilibrium phonon dynamics with ultrafast electron diffuse scattering
• Time- and angle-resolved photoemission spectroscopy of solids in the extreme ultraviolet at 500 kHz repetition rate
• Momentum-resolved observation of exciton formation dynamics in monolayer WS${}_2$
• Direct measurement of key exciton properties: energy, dynamics and spatial distribution of the wave function
• Ultrafast extreme ultraviolet photoemission without space charge
• Revealing Hidden Orbital Pseudospin Texture with Time-Reversal Dichroism in Photoelectron Angular Distributions
• High-energy photoemission on Fe3O4: Small polaron physics and the Verwey transition
• Directly characterizing the relative strength and momentum dependence of electron-phonon coupling using resonant inelastic x-ray scattering
• Time- and momentum-resolved photoemission studies using time-of-flight momentum microscopy at a free-electron laser
• Spin-polarized Dirac-cone-like surface state with $d$ character at W(110)
• Temperature-dependent Fermi surface evolution in heavy fermion CeIrIn5
• XUV Frequency Combs via Femtosecond Enhancement Cavities
• How Circular Dichroism in time- and angle-resolved photoemission can be used to spectroscopically detect transient topological states in graphene
• Tracing orbital images on ultrafast time scales
• Time-Resolved Momentum Microscopy with a 1 MHz High-Harmonic Extreme Ultraviolet Beamline
• An experimental setup for high resolution 10.5 eV laser-based angle-resolved photoelectron spectroscopy using a time-of-flight electron analyzer
• Spin Mapping of Surface and Bulk Rashba States in Ferroelectric a-GeTe(111) Films
• Observation of an excitonic Mott transition through ultrafast core-$\text{cum}$-conduction photoemission spectroscopy
• A quantitative comparison of time-of-flight momentum microscopes and hemispherical analyzers for time- and angle-resolved photoemission spectroscopy experiments
• High energy photoelectron diffraction: model calculations and future possibilities
• Development of a technology for the fabrication of Low-Gain Avalanche Detectors at BNL
• Low-Temperature and High-Energy-Resolution Laser Photoemission Spectroscopy
• Operando imaging of all-electric spin texture manipulation in ferroelectric and multiferroic Rashba semiconductors
• Subpicosecond metamagnetic phase transition driven by non-equilibrium electron dynamics
• Tracking the time-evolution of the electron distribution function in Copper by femtosecond broadband optical spectroscopy
• Electromagnetic dressing of the electron energy spectrum of Au(111) at high momenta
• Fourfold Differential Photoelectron Circular Dichroism
• Multi-channel exchange-scattering spin polarimetry
• Observation of an optical non-Fermi-liquid behavior in the heavy fermion state of YbRh${}_2$Si${}_2$
• An efficient way to model complex magnetite: assessment of SCC-DFTB against DFT
• Efficient orbital imaging based on ultrafast momentum microscopy and sparsity-driven phase retrieval
• Polarization-Modulated Angle-Resolved Photoemission Spectroscopy: Towards Circular Dichroism without Circular Photons and Bloch Wavefunction Reconstruction
• Accessing the spectral function of in operando devices by angle-resolved photoemission spectroscopy
• Monitoring surface resonances on Co2MnSi(100) by spin-resolved photoelectron spectroscopy
• Single-Hemisphere Photoelectron Momentum Microscope With Time-of-Flight Recording
• Ultrafast electronic line width broadening in the C 1s core level of graphene
• Band structure tuning of Heusler compounds revisited: Spin- and momentum-resolved electronic structure analysis of compounds with different band filling
• Surface resonance of the Heusler half metal Co2MnSi probed by SX-ARPES
• Cation- and lattice-site-selective magnetic depth profiles of ultrathin $\mathrm{F}{\mathrm{e}}_3{\mathrm{O}}_4$(001) films
• Vectorial spin-polarization detection in multichannel spin-resolved photoemission spectroscopy using an Ir(001) imaging spin filter
• Spin-polarized electronic surface states of Re(0001): an ab-initio investigation
• Attosecond Intramolecular-Scattering and Vibronic Delay
• Moiré-localized interlayer exciton wavefunctions captured by imaging its electron and hole constituents